In the prior art, there are different LED packaging methods, including LED lamp package, Chip On Board LED package, Surface Mount Device LED package, System In Package LED package, etc., and different packaging substrate will be selected based on the LED packaging method.
In general, the substrate for the Chip On Board LED package is a substrate which is a circuit board or made of a single material, such as metal, PVC, Polymethyl methacrylate, plastic, etc., and the shape of the substrate is mostly a flat rectangle, a flat circular or flat strip, etc., and the edge of the substrate is usually smooth curve or straight line.
In addition, after the LED chips are disposed on the existing substrate and sealed with fluorescent glue, a planar light will be emitted. Even if a plurality of substrates are arranged to be a luminous body with three-dimensional shape, an uneven light emission often appear around the luminous body due to imperfect overall structure design. Furthermore, when the substrate is made of a light transparent material, the luminous body can emit light at a range of 360 degrees, but in this case, a problem of heat dissipation would arise. When the substrate is made of a non-transparent material, such as a metal, the side of the substrate that is not provided with the LED chip will not emit light such that the luminous body cannot emit light at 360-degree.
In conclusion, the existing Chip On Board LED package and bulb have not a full light emitting angle to achieve a multi-angle and multilevel light emitting, and are also prone to meeting the dissipation problem and affecting the luminous efficiency.